1. Field of the Invention
The present invention relates to a method and composition for sizing cellulosic fibers or cellulosic fiber-containing material.
2. Prior Art
Numerous compositions and methods have been suggested heretofore for sizing paper, i.e., rendering the paper more resistant to penetration by liquids. Materials such as resin, various hydrocarbon and natural waxes, starches, glues, casein, asphalt emulsions, synthetic resins and cellulose derivatives have been employed as sizing agents. See, e.g., U.S. Pat. Nos. 3,084,093; 3,084,092; 2,995,483; 2,964,445; 2,941,919; 2,903,391; 2,872,315; 2,830,916; 2,764,483; 2,684,300, and the like.
Typically, such derivatives are added directly to the paper making stock as "beater additives" and precipitated on the paper as it is formed to yield "internal" or "engine" sizing. Alternatively, the paper sheet may be passed, after formation, through a size solution, or over a roll wetted with the size solution to produce "tub-sized" or "surface-sized" paper sheets.
Reagents containing functional groups or which are merely precipitated on paper which react with the cellulose content of paper have also been utilized as sizing agents.
For example, U.S. Pat. No. 3,050,437 discloses the use of hydrophobic isocyanates as tub-sizing agents.
U.S. Pat. No. 3,337,636 discloses that various substituted trisulfonylmethanes may be employed to size paper by precipitation thereof on the cellulose fibers of the paper.
Westfelt et al, Cellul. Chem. Technol., Vol. 17(2), pp. 165-77 (1983) discloses the utilization of certain sulfonyl reagents as wet strength additives for paper.
Lukyanwa, Tekst. Prom. (Moscow), Vol. 27(8), pp. 51-2 (1967) [Chemical Abstracts 68, 96720n (1968)] and Rabinovich et al, Khim. Tekhnol. Proizrod. Tsellyul (1968) pp. 148-56 [Chemical Abstracts, 72, 91609f (1970)] relate to the utilization of cellulose ethanesulfonate as a sizing agent for cellulose fibers. The derivative is, however, precipitated on the fibers.
U.S. Pat No. 4,043,863 discloses the use of sulfamoylchlorides as cellulose fiber sizing agents.
U.S. Pat. No. 3,576,712 relates to the use of a composition containing a 2-chloroalkyl sulfone, a 2-chloroalkyl sulfoxide or a 2-chloroalkyl sulfide as paper sizing agents.
In U.S. Pat. No. 4,551,201 there is described a method for tub- or surface-sizing paper and other cellulose fiber-containing substrates by reacting the cellulose fibers with a sizing agent having the formula: ##STR1## wherein: R.sub.1 is an alkyl group having from 1 to 5 carbon atoms, and
R is an alkyl group having from 12 to 24 carbon atoms. PA1 R is an alkyl group having from 12 to 24 carbon atoms, and PA1 n is an integer from 0 to 4. PA1 R is an alkyl group having from 12 to 24 carbon atoms, and PA1 n is an integer from 0 to 4. PA1 R is an alkyl group of 12 to 24 carbon atoms, and PA1 n is an integer from 0 to 4.
The method, however, generally requires the use of organic solvents since the sulfonates are either insoluble in water or will not react with cellulose in emulsion form. Moreover, it is usually necessary to conduct the reaction at an akaline pH, preferably after pre-treating the substrate with a suitable base, followed by drying. Finally, it is necessary to remove excess organic solvent and base following the reaction, thereby adding to the overall cost and decreasing the efficiency of the method.
It is an object of the present invention to provide a novel composition and method for sizing cellulose fiber containing substrates based on the use of certain long chain alkyl sulfonates which are not subject to the disadvantages associated with the method and composition described in U.S. Pat. No. 4,551,201.